Putative ABC Transporter Research Articles

Salt tolerance of a Sinorhizobium meliloti strain isolated from dry lands: growth capacity and protein profile changes

Sinorhizobium meliloti strain A5, isolated from root nodules of Medicago truncatula growing spontaneously in Tunisian dry lands, showed better growth performance under different sodium chloride concentrations than the standard reference strain RCR2011. Strain A5 has the ability to grow even at 684 mM NaCl. Two-dimensional (2D) electrophoretic analysis of the salt effect on proteome profiles revealed the greatest change on the 4th day of exposure. The halotolerant strain A5 showed more upregulated protein spots than the standard RCR2011 strain (23% of the analyzed protein spots vs only 10% in strain RCR2011) and fewer downregulated protein spots (28% vs 69%). Proteins over-expressed in salty medium as determined by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry for both strains were identified as an outer-membrane protein, an l-amino-acid binding periplasmic transporter protein, a 50S ribosomal protein (L25), a heat shock protein, and a putative oxido-reductase protein. Down-regulated proteins were identified as a putative iron-binding periplasmic transporter protein, a putative lipoprotein precursor, a putative spermidine/putrescine-binding periplasmic transporter protein, and a putative amino-acid binding ABC transporter protein. The profile of strain A5 showed higher over-expression of an oxidoreductase and a heat-shock protein, and specifically an induction of a putative oligopeptide ABC transporter ATP-binding protein.

Expression of the Streptomyces coelicolor SoxR Regulon Is Intimately Linked with Actinorhodin Production

The [2Fe-2S]-containing transcription factor SoxR is conserved in diverse bacteria. SoxR is traditionally known as the regulator of a global oxidative stress response in Escherichia coli, but recent studies suggest that this function may be restricted to enteric bacteria. In the vast majority of nonenterics, SoxR is predicted to mediate a response to endogenously produced redox-active metabolites. We have examined the regulation and function of the SoxR regulon in the model antibiotic-producing filamentous bacterium Streptomyces coelicolor. Unlike the E. coli soxR deletion mutant, the S. coelicolor equivalent is not hypersensitive to oxidants, indicating that SoxR does not potentiate antioxidant defense in the latter. SoxR regulates five genes in S. coelicolor, including those encoding a putative ABC transporter, two oxidoreductases, a monooxygenase, and a possible NAD-dependent epimerase/dehydratase. Expression of these genes depends on the production of the benzochromanequinone antibiotic actinorhodin and requires intact [2Fe-2S] clusters in SoxR. These data indicate that actinorhodin, or a redox-active precursor, modulates SoxR activity in S. coelicolor to stimulate the production of a membrane transporter and proteins with homology to actinorhodin-tailoring enzymes. While the role of SoxR in S. coelicolor remains under investigation, these studies support the notion that SoxR has been adapted to perform distinct physiological functions to serve the needs of organisms that occupy different ecological niches and face different environmental challenges.

Overexpression of patA and patB , Which Encode ABC Transporters, Is Associated with Fluoroquinolone Resistance in Clinical Isolates of Streptococcus pneumoniae

Fifty-seven clinical isolates of Streptococcus pneumoniae were divided into four groups based on their susceptibilities to the fluoroquinolones ciprofloxacin and norfloxacin and the dyes ethidium bromide and acriflavine. Comparative reverse transcription-PCR was used to determine the level of expression of the genes patA and patB, which encode putative ABC transporters. Overexpression was observed in 14 of the 15 isolates that were resistant to both fluoroquinolones and dyes and in only 3 of 24 of those resistant to fluoroquinolones only. Isolates overexpressing patA and patB accumulated significantly less of the fluorescent dye Hoechst 33342 than wild-type isolates, suggesting that PatA and PatB are involved in efflux. Inactivation of patA and patB by in vitro mariner mutagenesis conferred hypersusceptibility to ethidium bromide and acriflavine in all isolates tested and lowered the MICs of ciprofloxacin in the patAB-overproducing and/or fluoroquinolone-resistant isolates. These data represent the first observation of overexpression of patA and patB in clinical isolates and show that PatA and PatB play a clinically relevant role in fluoroquinolone resistance.

Rv1218c, an ABC Transporter of Mycobacterium tuberculosis with Implications in Drug Discovery

Efflux systems are important in determining the efficacy of antibiotics used in the treatment of bacterial infections. In the last decade much attention has been paid to studying the efflux pumps of mycobacteria. New classes of compounds are under investigation for development into potential candidate drugs for the treatment of tuberculosis. Quite often, these have poor bactericidal activities but exhibit excellent target (biochemical) inhibition. Microarray studies conducted in our laboratories for deciphering the mode of action of experimental drugs revealed the presence of putative ABC transporters. Among these transporters, Rv1218c was chosen for studying its physiological relevance in mediating efflux in Mycobacterium tuberculosis. A ΔRv1218c mutant of M. tuberculosis displayed a 4- to 8-fold increase in the inhibitory and bactericidal potency for different classes of compounds. The MICs and MBCs were reversed to wild-type values when the full-length Rv1218c gene was reintroduced into the ΔRv1218c mutant on a multicopy plasmid. Most of the compound classes had significantly better bactericidal activity in the ΔRv1218c mutant than in the wild-type H37Rv, suggesting the involvement of Rv1218c gene product in effluxing these compounds from M. tuberculosis. The implication of these findings on tuberculosis drug discovery is discussed.

A Multitask ATPase Serving Different ABC-Type Sugar Importers in Bacillus subtilis

Bacillus subtilis is able to utilize arabinopolysaccharides derived from plant biomass. Here, by combining genetic and physiological analyses we characterize the AraNPQ importer and identify primary and secondary transporters of B. subtilis involved in the uptake of arabinosaccharides. We show that the ABC-type importer AraNPQ is involved in the uptake of α-1,5-arabinooligosaccharides, at least up to four L-arabinosyl units. Although this system is the key transporter for α-1,5-arabinotriose and α-1,5-arabinotetraose, the results indicate that α-1,5-arabinobiose also is translocated by the secondary transporter AraE. This broad-specificity proton symporter is the major transporter for arabinose and also is accountable for the uptake of xylose and galactose. In addition, MsmX is shown to be the ATPase that energizes the incomplete AraNPQ importer. Furthermore, the results suggest the existence of at least one more unidentified MsmX-dependent ABC importer responsible for the uptake of nonlinear α-1,2- and α-1,3-arabinooligosaccharides. This study assigns MsmX as a multipurpose B. subtilis ATPase required to energize different saccharide transporters, the arabinooligosaccharide-specific AraNPQ-MsmX system, a putative MsmX-dependent ABC transporter specific for nonlinear arabinooligosaccharides, and the previously characterized maltodextrin-specific MdxEFG-MsmX system.

The ABC‐transporter hutCD genes of Photobacterium damselae subsp. piscicida are essential for haem utilization as iron source and are expressed during infection in fish

The marine fish pathogen Photobacterium damselae subsp. piscicida utilizes haem compounds as the sole iron source. In a previous work, we characterized a gene cluster with ten potential haem uptake and utilization genes. Two of these genes, hutC and hutD, which are iron-regulated, conform a putative inner membrane haem ABC transporter. In this study, we constructed an insertional mutant, leading to the inactivation of hutCD genes. Reverse transcriptase-PCR analyses demonstrated that an insertion between the hutB and hutC genes abolished transcription of the downstream hutC and hutD genes. The hutCD mutant was unable to utilize haem as the sole iron source, demonstrating that the putative ABC-transporter proteins HutC and HutD are essential for haem utilization as an iron source in P. damselae subsp. piscicida. In addition, reverse transcriptase-PCR assays conducted with RNA samples isolated from experimentally infected fish revealed the presence of hutCD transcripts. The results demonstrate for the first time that haem uptake genes of a fish pathogen are expressed during the infective process in fish.

Silica deposition and phenotypic changes to Thermus thermophilus cultivated in the presence of supersaturated silicia

Thermus thermophilus cells formed siliceous deposits in the presence of supersaturated silicic acid (600 p.p.m SiO(2)). The supersaturated silicic acid promoted interaction between cells and the inside walls of glass culture bottles, leading to the development of cell aggregates or biofilms. Electron probe microanalysis showed that within the aggregates most of the cell surfaces were covered with silica. Under these conditions, there was remarkable production of silica-induced protein (Sip), a solute-binding component of the Fe(3+)-binding ABC transporter. Furthermore, supersaturated silica enhanced resistance to the peptide antibiotics bacitracin, colistin and polymyxin B, which all act on the cell envelope. By contrast, supersaturated silica did not induce resistance to ampicillin, chloramphenicol, kanamycin and tetracycline, which inhibit peptide synthesis. Although strong expression of Sip was detected in liquid cultures of T. thermophilus in the presence of supersaturated silica and colistin, upregulated transcription of putative efflux pump and multidrug resistance ABC transporter genes were not detected by quantitative real-time PCR analysis. These findings suggest Sip promotes silica deposition on the surfaces of cells, after which the silicified outer membrane may serve as a 'suit-of-armor,' conferring resistance to peptide antibiotics.

Analyses of Bifidobacterial Glycosidases Involved in the Metabolism of Oligosaccharides

Many bifidobacteria produce an endo-α-N-acetylgalactosaminidase that liberates the O-linked galactosyl β-1,3N-acetylgalactosamine (GNB) from intestinal mucin glycoproteins. The molecular cloning of the Bifidobacterium longum enzyme was completed using information in public databases. The enzyme constitutes a novel glycoside hydrolase (GH) family 101 member. The gene encoding a specific 1,2-α -L-fucosidase was cloned from B. bifidum. The recombinant enzyme specifically hydrolyzes the terminal α-1,2-fucosidic linkages of various oligosaccharides, including human milk oligosaccharides and blood group substances. Analysis of its primary structure revealed that this enzyme constitutes a novel GH family 95 member. We also solved the crystal structure of its catalytic domain. We assumed that these bifidobacterial enzymes are involved in the metabolism of oligosaccharides in mucin glycoproteins that are abundant in the intestine. Some bifidobacteria strains produce a lacto-N-biosidase that releases galactosyl β- 1,3N-acetylglucosamine (LNB) from human milk oligosaccharides, but the other enteric bacteria do not. This disaccharide is one of the building blocks in human milk oligosaccharides and is rarely found in other mammalian milks. The lacto-N-biosidase gene was cloned from B.bifidum and we hypothesized that this enzyme is crucially involved in the degradation of human milk oligosaccharides. The genes encoding sialidase and α-1,3/4-L-fucosidase were also cloned from B.bifidum. These enzymes release modified sialic acid and L-fucose from human milk oligosaccharides, respectively. A solute-binding protein of a putative ABC transporter specific for GNB and LNB was also discovered, and its gene was cloned from B.longum. We named it GNB/LNB-binding protein and crystallized it. Isothermal titration calorimetry measurements revealed that this protein specifically binds GNB and LNB. We speculate that bifidobacteria have a novel GNB/LNB metabolic pathway.

Generic and Specific Adaptive Responses ofStreptococcus pneumoniaeto Challenge with Three Distinct Antimicrobial Peptides, Bacitracin, LL-37, and Nisin

To investigate the response of Streptococcus pneumoniae to three distinct antimicrobial peptides (AMPs), bacitracin, nisin, and LL-37, transcriptome analysis of challenged bacteria was performed. Only a limited number of genes were found to be up- or downregulated in all cases. Several of these common highly induced genes were chosen for further analysis, i.e., SP0385-SP0387 (SP0385-0387 herein), SP0912-0913, SP0785-0787, SP1714-1715, and the blp gene cluster. Deletion of these genes in combination with MIC determinations showed that several putative transporters, i.e., SP0785-0787 and SP0912-0913, were indeed involved in resistance to lincomycin and LL-37 and to bacitracin, nisin, and lincomycin, respectively. Mutation of the blp bacteriocin immunity genes resulted in an increased sensitivity to LL-37. Interestingly, a putative ABC transporter (SP1715) protected against bacitracin and Hoechst 33342 but conferred sensitivity to LL-37. A GntR-like regulator, SP1714, was identified as a negative regulator of itself and two of the putative transporters. In conclusion, we show that resistance to three different AMPs in S. pneumoniae is mediated by several putative ABC transporters, some of which have not been associated with antimicrobial resistance in this organism before. In addition, a GntR-like regulator that regulates two of these transporters was identified. Our findings extend the understanding of defense mechanisms of this important human pathogen against antimicrobial compounds and point toward novel proteins, i.e., putative ABC transporters, which can be used as targets for the development of new antimicrobials.

한국인 우식아동으로부터 분리한 Streptococcus mutans의 내산성 단백질의 발현

본 연구에서는 한국인 아동의 우식치아로부터 S. mutans를 분리하고, acid stress하에서 분리한 S. mutans의 내산성 능력과 관련된 단백질을 규명하고자 하였다. 2D gel electrophoresis를 수행한 결과, acid stress동안 elongation factor Ts, hypothetical protein, putative amino acid ABC transporter, adenylate kinase, fructokinase, Putative 40K cell well protein precursor, peptide deformylase, shikimate 5-dehydrogenase, mannose-6-phosphate isomerase, threonine synthase, putative dTDP-glucose-4,6-dehydratase의 발현량이 뚜렷이 증가하였으며 이들 단백질은 acid stress에 관여하는 단백질들로 추정된다. In this study, we are interested in comparing the protein profiles of acid-shocked and control cells of S. mutans isolated from Korean children with caries. The results of 2D gel electrophoresis showed that twelve proteins are up-regulated when the cells were grown under 20 mM lactic acid stress in the exponential phase. Up-proteins under acid stress were estimated a major key of the survival and proliferation of S. mutans in low pH environments. These proteins are estimated generally associated with three biochemical pathways: glycolysis, alternative acid production and branched-chain amino acid biosynthesis.

A Trilocus Sequence Typing Scheme for Hospital Epidemiology and Subspecies Differentiation of an Important Nosocomial Pathogen, Enterococcus faecalis

In this study, we present a trilocus sequence typing (TLST) scheme based on intragenic regions of two antigenic genes, ace and salA (encoding a collagen/laminin adhesin and a cell wall-associated antigen, respectively), and a gene associated with antibiotic resistance, lsa (encoding a putative ABC transporter), for subspecies differentiation of Enterococcus faecalis. Each of the alleles was analyzed using 50 E. faecalis isolates representing 42 diverse multilocus sequence types (ST(M); based on seven housekeeping genes) and four groups of clonally linked (by pulsed-field gel electrophoresis [PFGE]) isolates. The allelic profiles and/or concatenated sequences of the three genes agreed with multilocus sequence typing (MLST) results for typing of 49 of the 50 isolates; in addition to the one exception, two isolates were found to have identical TLST types but were single-locus variants (differing by a single nucleotide) by MLST and were therefore also classified as clonally related by MLST. TLST was also comparable to PFGE for establishing short-term epidemiological relationships, typing all isolates classified as clonally related by PFGE with the same type. TLST was then applied to representative isolates (of each PFGE subtype and isolation year) of a collection of 48 hospital isolates and demonstrated the same relationships between isolates of an outbreak strain as those found by MLST and PFGE. In conclusion, the TLST scheme described here was shown to be successful for investigating short-term epidemiology in a hospital setting and may provide an alternative to MLST for discriminating isolates.

A Putative ABC Transporter Confers Durable Resistance to Multiple Fungal Pathogens in Wheat

Agricultural crops benefit from resistance to pathogens that endures over years and generations of both pest and crop. Durable disease resistance, which may be partial or complete, can be controlled by several genes. Some of the most devastating fungal pathogens in wheat are leaf rust, stripe rust, and powdery mildew. The wheat gene Lr34 has supported resistance to these pathogens for more than 50 years. Lr34 is now shared by wheat cultivars around the world. Here, we show that the LR34 protein resembles adenosine triphosphate-binding cassette transporters of the pleiotropic drug resistance subfamily. Alleles of Lr34 conferring resistance or susceptibility differ by three genetic polymorphisms. The Lr34 gene, which functions in the adult plant, stimulates senescence-like processes in the flag leaf tips and edges.

Characterization of an ATP-binding cassette from Clostridium perfringens with homology to an ABC transporter from Clostridium hathewayi

A ciprofloxacin-resistant mutant of Clostridium perfringens, strain VPI-C, which had stable mutations in the topoisomerase genes, accumulated less norfloxacin and ethidium bromide than the wild type, strain VPI. Efflux pump inhibitors both increased the accumulation of ethidium bromide by cells of the mutant and enhanced their sensitivity to this toxic dye. Cloning a gene, which codes for a putative ABC transporter protein ( NP_562422) of 527 amino acids, from the mutant strain VPI-C into the wild-type strain VPI not only reduced the accumulation of ethidium bromide by the recombinant strain but also reduced its sensitivity to norfloxacin and ciprofloxacin. Efflux pump inhibitors decreased the rate at which ethidium bromide was removed from the cells of the recombinant strain. It appears that the putative ABC transporter protein ( NP_562422) may contribute to extrusion of drugs from C. perfringens.

A Neisseria meningitidis NMB1966 mutant is impaired for invasion of respiratory epithelial cells, survival in human blood and for virulence in vivo

We sought to determine whether NMB1966, encoding a putative ABC transporter, has a role in pathogenesis. Compared to its isogenic wild-type parent strain Neisseria meningitidis MC58, the NMB1966 knockout mutant was less adhesive and invasive for human bronchial epithelial cells, had reduced survival in human blood and was attenuated in a systemic mouse model of infection. The transcriptome of the wild-type and the NMB1966 mutant was compared. The data are consistent with a previous functional assignment of NMB1966 being the ABC transporter component of a glutamate transporter operon. Forty-seven percent of all the differentially regulated genes encoded known outer membrane proteins or pathways generating complex surface structures such as adhesins, peptidoglycan and capsule. The data show that NMB1966 has a role in virulence and that remodelling of the outer membrane and surface/structures is associated with attenuation of the NMB1966 mutant.

Expression and Physiological Relevance of Agrobacterium tumefaciens Phosphatidylcholine Biosynthesis Genes

Phosphatidylcholine (PC), or lecithin, is the major phospholipid in eukaryotic membranes, whereas only 10% of all bacteria are predicted to synthesize PC. In Rhizobiaceae, including the phytopathogenic bacterium Agrobacterium tumefaciens, PC is essential for the establishment of a successful host-microbe interaction. A. tumefaciens produces PC via two alternative pathways, the methylation pathway and the Pcs pathway. The responsible genes, pmtA (coding for a phospholipid N-methyltransferase) and pcs (coding for a PC synthase), are located on the circular chromosome of A. tumefaciens C58. Recombinant expression of pmtA and pcs in Escherichia coli revealed that the individual proteins carry out the annotated enzyme functions. Both genes and a putative ABC transporter operon downstream of PC are constitutively expressed in A. tumefaciens. The amount of PC in A. tumefaciens membranes reaches around 23% of total membrane lipids. We show that PC is distributed in both the inner and outer membranes. Loss of PC results in reduced motility and increased biofilm formation, two processes known to be involved in virulence. Our work documents the critical importance of membrane lipid homeostasis for diverse cellular processes in A. tumefaciens.

A novel streptococcal integrative conjugative element involved in iron acquisition

In this study, we determined the function of a novel non-ribosomal peptide synthetase (NRPS) system carried by a streptococcal integrative conjugative element (ICE), ICESe2. The NRPS shares similarity with the yersiniabactin system found in the high-pathogenicity island of Yersinia sp. and is the first of its kind to be identified in streptococci. We named the NRPS product ‘equibactin’ and genes of this locus eqbA–N. ICESe2, although absolutely conserved in Streptococcus equi, the causative agent of equine strangles, was absent from all strains of the closely related opportunistic pathogen Streptococcus zooepidemicus. Binding of EqbA, a DtxR-like regulator, to the eqbB promoter was increased in the presence of cations. Deletion of eqbA resulted in a small-colony phenotype. Further deletion of the irp2 homologue eqbE, or the genes eqbH, eqbI and eqbJ encoding a putative ABC transporter, or addition of the iron chelator nitrilotriacetate, reversed this phenotype, implicating iron toxicity. Quantification of 55Fe accumulation and sensitivity to streptonigrin suggested that equibactin is secreted by S. equi and that the eqbH, eqbI and eqbJ genes are required for its associated iron import. In agreement with a structure-based model of equibactin synthesis, supplementation of chemically defined media with salicylate was required for equibactin production.

Proteomics Analysis of Drought Stress-Responsive Proteins in Hippophae rhamnoides L.

Hippophae rhamnoides L. is uniquely capable of growing well under extreme environmental conditions such as water deficit, low temperature, and high altitude. Such tolerance invokes much interest in understanding the biology of this plant species and its utilization potential. In this study, analysis of drought stress-responsive proteins in H. rhamnoides was conducted wherein greenhouse-grown seedlings were subjected to drought stress. By using proteomic techniques, proteins, extracted from leaves, were analyzed using two-dimensional electrophoresis and MALDI-TOF MS. Altogether, 55 proteins exhibited changes in abundance under stress. Of these, 13 proteins were identified, including three that disappeared under drought (a putative ABC transporter ATP-binging protein, a heat shock protein HslU, and a hypothetical protein XP-515578), seven that were up-regulated (three large subunits of rubisco, a hypothetical protein DSM3645–23351, a putative acyl-CoA dehydrogenase, a nesprin-2, and a J-type co-chaperone HSC20), and three that were only detected under drought (a probable nitrogen regulation protein (NtrX), a 4-hydroxyphenylpyruvate dioxygenase, and an unnamed protein product). These proteins may function in β-oxidation pathways in mitochondria, across membranes transport, abnormal protein removal, or prevent protein aggregation arrest, cell division, cytoskeleton stabilization, iron–sulfur cluster assembly, nitrogen metabolism regulation, and antioxidant substance biosynthesis. Four proteins (J-type co-chaperone Hsc20, a putative ABC transporter ATP-binging protein, NtrX, and HslU) were deemed as new discoveries in higher plants, and their functions were predicted either from their conserved domains or homologies to other organisms. These results provide new insights into our understanding of the mechanism of drought tolerance in plants.

Regulation of Fructose Transport and Its Effect on Fructose Toxicity in Anabaena spp

Anabaena variabilis grows heterotrophically using fructose, while the close relative Anabaena sp. strain PCC 7120 does not. Introduction of a cluster of genes encoding a putative ABC transporter, herein named frtRABC, into Anabaena sp. strain PCC 7120 on a replicating plasmid allowed that strain to grow in the dark using fructose, indicating that these genes are necessary and sufficient for heterotrophic growth. FrtR, a putative LacI-like regulatory protein, was essential for heterotrophic growth of both cyanobacterial strains. Transcriptional analysis revealed that the transport system was induced by fructose and that in the absence of FrtR, frtA was very highly expressed, with or without fructose. In the frtR mutant, fructose uptake was immediate, in contrast to that in the wild-type strain, which required about 40 min for induction of transport. In the frtR mutant, high-level expression of the fructose transporter resulted in cells that were extremely sensitive to fructose. Even in the presence of the inducer, fructose, expression of frtA was low in the wild-type strain compared to that in the frtR mutant, indicating that FrtR repressed the transporter genes even in the presence of fructose. FrtR bound to the upstream region of frtA, but binding was not visibly altered by fructose, further supporting the hypothesis that fructose has only a modest effect in relieving repression of frtA by FrtR. A. variabilis grew better with increasing concentrations of fructose up to 50 mM, showing increased cell size and heterocyst frequency. Anabaena sp. strain PCC 7120 did not show any of these changes when it was grown with fructose. Thus, although Anabaena sp. strain PCC 7120 could take up fructose and use it in the dark, fructose did not improve growth in the light.

Poly-3-hydroxybutyrate Synthase from the Periplasm of Escherichiacoli

This is the first report of a poly-3-hydroxybutyrate (PHB) synthase in Escherichia coli. The enzyme was isolated from the periplasm using ammonium sulfate fractionation, hydrophobic, and size-exclusion chromatography and identified by LC/MS/MS as YdcS, a component of a putative ABC transporter. Green Fluorescent Protein-tagged ydcS, purified by 2D native gel electrophoresis, also exhibited PHB synthase activity. Optimal conditions for enzyme activity were 37 °C, pH 6.8–7.5, 100 mM KCl. K m was 0.14 mM and V max was 18.7 nmol/mg protein/min. The periplasms of deletion mutants displayed <25% of the activity of the parent strain. Deletion mutants exhibited ∼25% less growth in M9 medium, glucose, and contained ∼30% less PHB complexed to proteins (cPHB) in the outer membranes, but the same concentration of chloroform-extractable PHB as wild-type cells. The primary sequence of YdcS suggests it may belong to the α-/β-hydrolase superfamily which includes polyhydroxybutyrate (PHB) synthases, lipases, and esterases.

Purification, crystallization and preliminary X-ray diffraction analysis of the putative ABC transporter ATP-binding protein from Thermotoga maritima.

Adenosine triphosphate (ATP) binding cassette transporters (ABC transporters) are ATP hydrolysis-dependent transmembrane transporters. Here, the overproduction, purification and crystallization of the putative ABC transporter ATP-binding protein TM0222 from Thermotoga maritima are reported. The protein was crystallized in the hexagonal space group P6(4)22, with unit-cell parameters a = b = 148.49, c = 106.96 A, gamma = 120.0 degrees . Assuming the presence of two molecules in the asymmetric unit, the calculated V(M) is 2.84 A(3) Da(-1), which corresponds to a solvent content of 56.6%. A three-wavelength MAD data set was collected to 2.3 A resolution from SeMet-substituted TM0222 crystals. Data sets were collected on the BL38B1 beamline at SPring-8, Japan.